Ladder construction



Dec. 26, 1961 Filed Aug. 4. 1959 J. F. FIKE LADDER CONSTRUCTION 4Sheets-Sheet 1 INVENTOR Jmyzesll'll'e M fim ATTORNEYS Dec. 26, 1961Filed Aug. 4, 1959 J. F. F IKE LADDER CONSTRUCTION 4 Sheets-Sheet 2INVENTOR 3 JmJlT Zke w a fazwz ATTORNEYS J. F. FIKE LADDER CONSTRUCTIONDec. 26, 1961 4 Sheets-Sheet 3 Filed Aug. 4. 1959 INV EN TOR M851ATTORNEYS Dec. 26, 1961 J. F. FIKE 3,014,552

LADDER CONSTRUCTION Filed Aug. 4. 1959 4 Sheets-Sheet 4 IN VENTOR JamesEaw, mam

ATTORNEYS 3&143552 Patented Dec. 26, 1961 s,e14,552 LADDER CONSTRUTIONJames F. Film, 533 S. Keystone Ave, Indianapolis, Ind. Filed Aug. 4,1959, Ser. No. senses 2 Claims. (Cl. l82-27) This invention relates toladders and more particularly to ladders comprising a plurality ofpivotable end-to-end sections.

Various ladders heretofore have been known, which are composed ofmultiple longitudinal sections disposed end-to-end and pivoted togetherto permit adjustment of the sections to various angular positionsrelative to each other. Such prior art ladders have been attended byvarious disadvantages, including insuificient strength and complexconnections between the pivotable sections which are expensive anddifficult to operate and maintain.

To overcome the disadvantages of the prior art, it is an object of thisinvention to provide an improved, highly effective and versatile ladderof the multiple, pivotable section type characterized by great strengthand simple, easy to operate connections between the pivotable sections.

Generally described, the invention resides in an adjustable ladder whichcomprises a pair of sections disposed in end-to-end relationship. Eachof the ladder sections includes a pair of wooden rails connectedtogether in laterally spaced relationship by a plurality of transverserungs at longitudinally spaced locations. Each of the rails has a metalcore embedded longitudinally therewithin. The metal cores of theadjacent sections are pivotally connected together at the lower edges ofthe adjoining rails to connect the adjoining rails in contiguousend-to-end relationship and to permit relative downward pivoting of theadjoining sections about such connections. The cores extend from theconnections a substantial distance longitudinally into the rails and arefixed thereto. Further, connecting means are provided which areselectively adjustable to a first condition retaining the sections in afixed angular relationship, and to a second condition retaining thesections in a straight-line relationship.

The invention having been generally described, various preferredspecific embodiments thereof will now be set forth in detail withreference to the accompanying drawings in which:

FIGURE 1 is a plan view of one embodiment of ladder according to theinvention with all of the various sections retained in straight-linerelationship to form a continuous ladder;

FIGURE 2 is'a side elevation of the ladder of FIG- URE 1 illustrating inphantom lines the manner in which the sections may be retained at fixedangular relationships to enhance the versatility of the ladder;

FIGURE 3 is a side elevation of the ladder of FIG- URE I adjusted tofunction as a stepladder;

FIGURE 4 is a side elevation of the ladder of FIGURE 1 adjusted tofunction as a scaffold;

FIGURE 5 is a side elevation of the ladder of FIG- URE 1 in collapsedstorage position;

FIGURE 6 is a bottom view of the collapsed ladder shown in FIGURE 5;

FIGURE 7 is a fragmentary vertical sectional View taken along the line7-7 of FIGURE 1;

FIGURE 8 is a vertical sectional view of one of the ladder rails takenalong the line 88 of FIGURE 7;

FIGURE 9 is a fragmentary perspective view of the end of one of therails of the outer ladder sections;

FIGURE 10 is a vertical sectional view taken along the line lit-10 ofFIGURE 1;

FIGURE 11 is a bottom plan view of a modified embodiment of a ladderaccording to the invention;

FIGURE 12 is a detailed view of the joint between the sections of theladder of FIGURE 11; and

FIGURE 13 is an end view showing the ladder of FIGURE 11 in a collapsedcondition.

Depicted in FIGURE 1 is a ladder designated generally by the referencenumeral l and comprising a relatively short, central step section 2, apair of relatively long inner leg sections 3 and a pair of relativelylong outer leg sections 4. The inner sections 3 and the outer sections4- are positioned in end-to-end relationship on opposite sides of thecentral step section 2. The step section 2 comprises a pair of rails Sand 6. Each of the inner leg sections 3 comprises a pair of rails 7 and8. Each of the outer leg sections 4 comprises a pair of rails 11 and 12.In each of the sections, the rails are spaced laterally apart and areconnected by a plurality of transverse rungs 13 positioned atlongitudinally spaced locations.

Each of the rails and rungs of each of the sections is formed of wood.Each of the rails has embedded therein a metal core. As shown in FIGURE1, the step section 2 has a metal core 14; each of the inner legsections has a metal core 15; and each of the outer leg sections has ametal core 16. As best seen in FIGURES 7 and 8, each metal core of eachof the sections comprises a flat metal bar embedded in the lower portionof each rail along the vertical center line thereof. The long axis ofeach of the core bars extends vertically of its rail to provide maximumreinforcement against vertical bending of the rail. Desirably, the coresextend throughout the length of each of the ladder rails. It isespecially important that the cores extend throughout the length of therails of the step and inner leg sections because when the entire ladderis employed as a continuous beam, the maximum bending moment exists inthe central sections. The cores of each pair of adjoining ladder railsare pivotally connected by pin and socket connections 19. Theconnections 19 provide horizontal pivots at or near the plane of thelower faces of the ladder rails to permit each pair of adjoiningsections to be pivoted inwardly relative to each other. The end faces ofadjoining rails abut one another when the adjoining sections arepositioned in a straight-line relationship to each other.

When the inner legs 3 are pivoted downwardly until they extend at rightangles to the step section 2, as shown in FIGURE 5, the distance betweenthe lower faces of the inner leg sections, as measured in a directionparallel to the step section should be at least as great as the combinedwidth of the outer leg sections 4. This enables the outer leg sectionsto be pivoted downwardly until they are parallel to the inner legsections 3 and the inner leg sections then to be pivoted downwardlyuntil all four of the leg sections are parallel, as shown in FIGURE 5.With the sections thus folded, the ladder is in collapsed storagecondition. To enable this condition to be achieved, the outer legs 4 canbe no longer than the inner legs 3, unless the construction of theconnections 19 between the step section and the inner leg sections issuch as to leave a gap between the inner end faces of the inner legsections and the bottom face of the step section when the sections arefolded as shown in FIGURE 5. In this case, the outer leg sections couldbe slightly longer than the inner leg sections without binding againstthe step section when moved toward collapsed storage position. The outerleg sections, however, may be somewhat shorter than the inner legsections.

The rungslii are connected to each of the rails by inserting the rungsinto corresponding openings in the rails whereupon the rungs are bondedto the rails by any suitable adhesive.

As shown in FIGURES 3 and 4, means are provided to retain the inner legsections and the step section either in a fixed angular relationship, asshown in FIGURE 3, or alternatively, in a straight-line relationship, asshown in FIGURE 4. At the fixed angular relationship, the ladder may beemployed a a stepladder. At the straightline relationship, the laddermay b employed as a scaffolding (FIGURE 4) or as a continuous lengthladder (FIGURE 2). A bracket 22 is fastened, as by a plurality of bolts23, tothe inner side face of each of the opposing rails 5 and 6 of thestep section 2. The brackets 22 depend downwardly from the step sectionand each is pivotally connected by a pin 24 at its lower end to a pairof elongated links 25. The other end of each of the links 25 may beselectively attached to either of a pair of mounting elements 27 or 28.Such mounting elements are positioned on the inner side face of each ofthe inner leg section rails. Each of the mounting elements 27 and 28comprises a pin connected to the metal core of the rail on which it ismounted and has a threaded end protruding inwardly from the rail face.The pins 27 and 28 are spaced longitudinally along each rail on whichthey are mounted. The free end of each link 25 has an opening thereinwhich may receive a pin 27 or 28 and be fastened thereto by a wing nut29. The position and spacing of the mounting elements 27 and 28 and thelength of the links 25 are such that the inner leg sections and the stepsections are retained in straight-line relationship when the free endsof the links are attached to the inner pins 27, and in a fixed angularrelationship when the free ends of the links 25 are attached to theouter pins 28.

Further, means are provided to retain the inner and outer legs either ina straight-line relationship as shown in said lines in FIGURES 2 and 3,or in a fixed angular relationship as shown in phantom lines in FIGURE 2and in solid lines in FIGURE 4. In the former relationship, the laddermay be employed as a stepladder or as a continuous ladder. In the latterrelationship, the ladder may be employed as a scaffold. A pair ofmounting elements 31 and 32 are mounted on the inner and outer legsections 3 and 4 on opposite sides of the pivotal connectiontherebetween. Each of the mounting elements 31 and 2 comprises a pinthreadedly connected to a rail and having a head spaced outwardly fromthe outer side face of the rail. The pins 31 and 32 are positioned onlongitudinal lines near the tops of the rails above the pivotalconnection 19 between the leg sections 3 and 4. The positioning of thepins 31 and 32 is such that the line therebetween is above such pivotalconnection 19 when the leg sections 3 and 4 are in Straight-linerelationship; is below such pivotal connection 19 when the leg sections3 and 4 are in the fixed angular relationship; and in each case is equalin length. A link or strap 33 is pivotally connected at one end to thepin 31 and has a socket and a hook at its other end to permit connectionto the pin 32. The effective length of the link 33 is equal to thedistance between the pins 31 and 32 when the leg sections 3 and 4 are ineither the straight-line or fixed angular relationship. Thus, when theleg sections 3 and 4 are moved either to the straight-line or fixedangular relationships, the link 33 may be connected between the pins 31and 32 to retain the legs in such relationship.

A modified embodiment of a ladder according to the invention is shown inFIGURES 11 through 13 and is generally identified by the referencenumeral 51. The ladder 51 can be employed either as a straight elongatedladder, as shown in FIGURE 11, or as a stepladder, as shown in FIGURE12.

The ladder 51 comprises two sections 52 and 53, which are positioned incontiguous end-to-end relationship. The section 52 comprises a pair ofelongated generally parallel wooden rails 54 and 55 connected by aplurality of transverse wooden rungs 56 positioned at longitudinallyspaced locations. The rungs 56 are formed from round bars which arereceived in appropriate openings 62 in the rails 54 and 55. The section53 comprises a pair of generally parallel wooden rails 57 and 53 whichare connected by a plurality of transverse wooden rungs 59 positioned atlongitudinally spaced locations. Desirably, the rail 57 and 58 aretapered slightly outwardly toward their lower ends as is common instepladder construction. The rungs 59 are formed from flat boards whichare set in slots 61 in the rails 57 and 58. The slots 61 are so inclinedrelative to the axis of the rails that the rungs or steps 59 arepositioned approximately horizontally when the ladder 51 is employed asa stepladder, as shown in FIGURE 12. Preferably, the rungs 56 and 59 aresecured to their respective rails by glued connections but othersuitable connections may be employed.

Each of the rails 54, 55, 57 and 58 has embedded therein, a metal core63. Each metal core of each of the rails comprises a flat metal barembedded in the lower portion of each rail along the vertical centerline thereof. The long cross-sectional axis of each of the core barsextends vertically of its rail to provide maximum reinforcement againstvertical bending of the rail. The cores of each pair of adjoining ladderrails are pivotally connected by pin and socket connections 64. Theconnections 64 provide horizontal pivots at or near the plane of thelower faces of the ladder rails to permit the adjoining sections to bepivoted inwardly relative to each other.

' The end faces of adjoining rails abut one another when the adjoiningsections are positioned in a straight-line relationship to each other.As shown in FIGURE 12, the core bars 63 of the rails 54 and 55 areprovided with arcuate slots 65 to receive the ends of the rungs 56.

As shown in FIGURE 11, the cores 63 extend a substantial distance intotheir respective rails to provide maximum reinforcement against verticalbending of the rail because, when the ladder is employed as a straightelongated ladder, the maximum bending moment occurs at the connection 64and in the portions of the ladder sections adjoining the connection 64.In the embodiment of FIGURE 11, the cores extend approximately to themidpoint of the rails but, if desired, may extend throughout the lengthof the rails.

As best seen in FIGURE 12, means are provided to retain the laddersections 52 and 53, either in fixed angular relationship oralternatively in a straight line relationship. .In the fixed angularrelationship, shown in FIG- URE 12, the ladder may be employed as astepladder. In the straight-line relationship, shown in FIGURE 11, theladder may be employed as a continuous length ladder. A link or a strap66 is pivotally connected at one end to a pin or mounting element 67which is connected to the rail 54. A pair of pins or mounting elements68 and 69 are connected at spaced locations along the outer face of therail 53. Each of the pins 68 and 69 is adapted to receive a socket of ahooked end of the strap 66 opposite to the end connected to the pin 67.The pins 67 and 69 are positioned on longitudinal lines near the tops oftheir respective rails above the pivotal connection 64 between theladder sections 52 and 53. Thus the line between the pins 67 and 69 isabove the pivotal connection 64 when the sections 52 and 53 are instraight-line relationship. The spacing between the pins 67 and 69 issuch that the strap 66 may be connected therebetween to lock thesections 52 and 53 in the straight-line relationship. The pin 68 ispositioned such that the strap 66 may be connected between the pins 67and 68 to lock the sections 52 and 53 in the fixed angular relationshipshown in FIGURE 12. Thus, when the sections 52 and 53 are moved eitherto the straight-line or fixed angular relationships, the straps 66 maybe connected between the pin 67 and one of the pins 68 and 69 to retainthe sections in such relationship.

An identical connecting means comprising a link 66 and pins 67, 68 and69 are connected to the rails 55 and 58.

A tray 71 is pivotally connected between the rails 54 and 55 to supportpaint cans and the like when the ladder is employed as a stepladder. Thetray may be pivoted to an out-of-the-way position parallel With therails as shown in FIGURE 11.

There has been illustrated and described what is considered to becertain preferred ladder embodiments according to the invention. It willbe understood, however, that many modifications may be made by personsskilled in the art without departing from the scope of the invention asdefined in the appended claims.

I claim:

1. An adjustable ladder which comprises a relatively short centrallylocated step section, two pairs of relatively long leg sections disposedin end-to-end relation-ship on opposite ends of said step section, eachof said sections comprising a pair of wooden rails connected together inlaterally spaced relationship, with the rails of said leg sections beingconnected by a plurality of transverse rungs at longitudinally spacedlocations, each of said rails having a metal core embeddedlongitudinally therewithin and extending to each end thereof whichadjoins another section, the cores of at least the step section and theinner leg sections extending throughout the length thereof, the cores ofadjacent sections being pivotally connected together at the lower edgesof the adjoining rails to connect the adjoining rails in contiguousend-to-end relationship and to permit relative downward pivoting of eachpair of adjoining sections about said connections, connecting meansselectively adjustable to a first condition retaining the inner legsections and the step section in a straight'line relationship and theinner and outer leg sections in a fixed angular relationship and to asecond condition retaining the inner leg sections and the step sectionsin a fixed angular relationship and the inner and outer leg sections ina straight-line relationship, said connecting means including a pair ofbrackets connected to and depending from opposite sides of said stepsection, each-of said brackets having pivotally connected to the lowerend thereof one end of each of a pair of links,

and a plurality of pairs of fixed mountingelements, one pair of saidmounting elements being connected at longitudinally spaced locations tothe metal core of each of said inner leg sections, the other end of eachof said links being selectively attachable to either mounting element ofone of said pairs of mounting elements, the position and spacing of eachof said pairs of mounting elements and the length of each of said linksbeing such that said inner leg sections and said step section areretained in their straight-line and angular relationships when saidother ends of said links are attached to inner and outer ones,respectively, of said pairs of mounting elements.

2. An adjustable ladder as recited in claim 1 wherein said connectingmeans further includes a plurality of pairs of second mounting elementsand a plurality of straps, each pair of said second mounting elementsbeing mounted at positions spaced above and on opposite sides of thepivotal connections between adjoining inner and outer leg sections, andeach of said straps being connectable between a pair of said secondmounting elements to fix the relative position of the associated legsections in either of their straight-line or fixed angularrelationships.

References Cited in the file of this patent UNITED STATES PATENTS

